Re: [CAD_CAM_EDM_DRO] Mach3 & laptops

gcode fi (hanermo) wrote:

> Well - it´s always good to think and look for solutions..
>
> Artsoft does not rely on "some specific behavior of the parallel port ".
> It writes directly to the port outside windows control at ring 0 on the
> processor.
> There is *no driver* in use.
> There are not any windows-specific "virtual ports" in use.
>
> This is an elegent solution since it solves the windows-created problem
> of non-specific timing.
>
> Thats why a usb solution must be either a smart solution like the SS
> (and the gecko g-rex) or absolutely transparent hardware solution.
> And also why you cannot use a "usb endpoint with timing" as there is no
> virtual driver.
> There is no windows involved it the driver - none. The data is pumped to
> the parallel port, and sync is maintained by the driver itself. No
> windows services are available at ring 0, nor are they used. The driver
> then gives temporary control back to windows on the 40 us ticks.
>
> Just thought I´d mention it.

That sums it up nicely!
While some older laptops are available with a 'real' parallel port and many of
these are in use with Mach3. The newer laptops - IF they have a 25 way
connector for the parallel port - implement it via a separate 'USB' chip
internally to cut down on real estate. In most cases nowadays you simply will
not have a parallel ( or serial ) port on the laptop, and need to use an
external USB box to provide them. Which will not then work with legacy kit
using the speed of the parallel port to achieve their performance.

Art's original comment about the power save functions does have a bearing, but
I think that in most cases now, as long as a PHYSICAL port exists and the
machine is at least 1GHz then it will work with Mach3. There were a few
niggles with the ITX based machines as well so this is not simply restricted
to laptops, but rather the newer lower power options on computer hardware.

--
Lester Caine - G8HFL
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